Ignition device



Dec. 27, 1966 HANS sTADLl-:R UAL l 3,294,020

IGNITION DEVICE Filed Jan. 25, 1965 INVENT ORS.

HANS S ER HEINZ IC HELLMUT BEN BY am* ATTORNEYS United States Patent O 3,294,020 IGNITION DEVICE Hans Stadler, Nurnberg, and Heinz Gawlick and Hellmut Bendler, Furth, Bavaria, Germany, assignors to Dynamit Nobel Aktiengesellschaft, Troisdorf, Germany Filed Jan. 25, 1965, Ser. No. 427,616

Claims priority, application Germany, llan. 24, 1964,

12 Claims. (Cl. 102-39) The present invention relates to an ignition device, 1and more particularly to long-burning ignition means for gas mixtures, especially in combustion engines.

Under certain prerequisites and operating conditions `gas mixtures containing air or oxygen can Ibe ignited only by means of Ia hot ignition llame burning over a longer period of time. This is the case, for example, 4with certain power engines or motors opera-ted with gase-ofus propellants. One has utilized heretofore for such purposes socaliled ignition lighters which are ignited outside `of t-he engine or motor and ignite the propellant mixture after insertion through an aperture into -t'he interior of the motor or engine. Aside from the resulting complicated handling of surch prior art ignition lighters, one has to accept the disadvantage that strong residues may occur which act in a corrosive manner on the engine or engine parts, especially in the presence of chlorine or sulphurcontaining residues.

Disadvantages of this type are avoided by the present invention -in that the ignition ame is produced by burning down a hollow :cylinder of powder accommodated in a cartridge case and essentially consisting of :components non-'dangerous -to corrosion, which is caused to burn `down in the direction from the cartridge case end iby the ignition jet penetrating through the cylinder channel and produced by an ignition means arranged in the bottom piece of the cartridge. A cartridge of this ltype can be ignited externally `by an extremely simple striker mechanism having a striker pin or .by an electric lfuse or primer. Corrosion-dangerous residues do not occur with such an arrangement; for insofar as the ignition means contains any corrosion-dangerous components at all, they represent only a minimum -fraction of the cor-responding residues of a prior art ignition lighter.

The ignition composition of the ignition 'device is so mixed Iand compounded according to a further ,feature of the present invention that it Idoes not produce during penetration through the hollow cylinder the heat required for the ignition of the powder. Instead, one of several foils are placed over the hollow cylinder of powder which are ignited by the ignition jet and which only in `their turn cause ignition of the powder composition.

With several powder foils disposed adjacent one another, the innermost foil is appropriately notched, grooved, or perforated and the rims of the apertures or perforations are bent inwardly so that the ignition by means of the ignitionjet becomes particularly safe. The powder Kfoils or sheets in general will be at a distance of 30 to 70 mm. from the primer lor tuse.

The ignition composition and powder foils are made appropriately of the same powder mass. Particularly favorable fo-r such mass is 'a mixture of nitrocellulose and nitroglycerine and/ or nitroglycol. This mixture can be readily manufactured and handled.

In one test with a blank of about 30 mm. in length, an external diameter of 16 mm. and an internal diameter of 6` mm., a burning duration lof 22 to 130 seconds was achieved with the present invention. By increasing the length of the powder body, the burning duration may be correspondingly increased. The burning duration is `constant with sucient certainty. If one desires to reinforce the flame, then the outer diameter of the blank will be increased with the same inner diameter. The burning duration may also be correspondingly reduced by shortening the length ofthe blank.

Accordingly, it is an object of the present invention to provide an ignition device for gas mixtures which obviates the aforementioned' short-comings and drawbacks encountered by -the prior art constructions by extremely simple means.

Another object of the present invention resides in the provision of ignition means for gas mixtures which assure with reliable certainty a given burning duration over relatively long period of time.

A furthe-r object of the present invention resides in the provision of an ignition device, especially Afor engines operating with propellants consisting of gas mixtures that permit simple handling lduring -the ignition of such engines.

Still another object of the present invent-ion resides in the provision o-f an ignition device for igniting gas mixtures, especially in power engines, which minimizes the danger of corrosion producing residues.

Still another object of the .present invention resides in the provision of an ignition device of the type described above which is not only extraordinarily safe and reliable in operation but also permits the use of powder mixtures that can be readily manufactured and handled.

A -furt-he-r object of the pre-sent invention resides in the provision of an ignition ymeans -for gas mixtures of engines which is relatively simple in structure, inexpensive in manufacture and constant in its Iburning duration.

These and other objects, features, and advantages of the present inventionl will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and in which the single ligure thereof is a cross-sectional vie`w through one embodiment in accordance with .the present invention.

Referring now to the single figure of the drawing, the ignition device in accordance with the present invention has about the shape of a sporting cartridge with a case 1 and a bottom piece 5. In the embodiment it is assumed that the case 1 is made in one piece with the bottom piece 5, especially of 'conventional plastic material. A primer or `fuse 2 of conventional construction is inserted into the bottom piece 5. The burn-ing charge 3 is constituted by a blank provided with a free internal channel 6. A number of powder foils yor sheets 4 are pla-ced over the blank 3 which are held in place by the flanged-over rim 7 of the case 1. The foils 4 are apertured and the aperture rims are bent inwardly Vat 8.

While we have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art and we therefore do not wish to be limited by the details shown and `described herein but intend to cover all such changes and modifications as are encompassed -by the scope of the lappended claims.

We claim:

1. A cartridge -for igniting gas mixtures with air or oxygen requiring a hot ignition flame burning for a relatively long period of time, especially for gaseous propellants of engines, comprising a generally tubular oase having rearward and forward ends; a bottom piece substantially closing the rearward end of said case; Ia generally tubular 'burning charge within said case forming a generally axially extending tiring channel substantially void of propellant change; means at the forward end of said case adjacent to said charge for igniting said burn-ing charge including at least one sheet of ignition powder extending generally transverse to the axis of said chanel; said sheet being provided with at least one aperture aligned with said channel; the area of the cross section of said aperture being substantially less than the area of the cnoss section of said channel; sheet means adjacent said apertured sheet for completely closing said aperture and said channel; and said sheet and sheet means being the sole end closure for said cartridge case.

2. The cartridge according to claim 1, wherein said .sheet adjacent said `aperture is bent substantially rearwardly into said channel progressively toward the cartridge axis.

3. The cartridge according to claim 2, including additional apertured sheets of ignition powder substantially identical to and in axially stacked engagement with said first-mentioned apertured sheet.

4. The cartridge according to claim 3 wherein each of said apertured sheet is substantially foil-like; said case and said bottom piece being `hon'logeneo'usly constructed of plastic; Vthe forward portion of said case being provided with an inwardly directed substantially annular ange; said ange directly engaging said sheet means and tightly pressing said sheets into direct engagement with the forward portion of said burning charge; primer means within said bottom piece aligned with said channel for projecting an ignition flame through said channel `and directly onto said sheets for igniting said sheets prior to the ignition of said charge; said burning charge consisting essentially of nitrocellulose and one or 'more of the substances selected from the group consisting of nitroglycol and nitroglycerine; said burning charge having a residue that is substantially non-corrosive.

5. The cartridge according to claim 1 including additional apertured sheets of ignition powder substantially identical to .and in axially stacked engagement with said firstmentioned apertured sheet.

G. The cartridge according to cilairn 5, wherein said apertured sheet is substantially foil-like.

7. The cartridge according to claim S, wherein said burning charge consists essentially `of nitrocellulose and at least one ofthe compounds selected `from the group consisting of nitroglycerine and nitnoglycol; said burning charge having a substantially non-corrosive residue.

8. The cartridge according to claim 1, wherein each of said apertured sheet and sheet means is constructed as a foil.

9. The cartridge according to claim 8, wherein said sheet adjacent said aperture is bent substantially rearwardly into said channel progressively toward the cartridge axis.

10. The `cartridge according to claim 8, wherein said burning charge `consists essentially of nitrocellulose and at least one of the `compounds selected from the group consisting of nitroglyce'rine and nitro-glycol; said burning charge having a substantially non-'corrosive residue.

11. The cartridge according to claim 1, wherein said burning charge consists essentially of nitrocellulose and at least one `'of the compounds selected from the group consisting of nitroglycerine and nitroglycol, said burning charging having a substantially non-corrosive residue.

12. The cartridge `according to claim 11, wherein said sheet adjacent said aperture is -bent substantially rearwardly into said channel progressively toward the cartridge axis.

References Cited by the Examiner UNITED STATES PATENTS 2,436,305 2/1948 Johnson 102-39 2,518,958 8/1950 Thomson et al. 102-39 2,740,356 4/1956 Millns 102-39 2,942,547 6/1960 Rabern et al. 102-39 2,959,001 ll/l960 Porter -35.6

OTHER REFERENCES Rocket Propulsion Elements, by Sutton, 1949, pp. 274- 275.

BENIAMIN A. BORCHELT, Primary Examiner.

ROBERT F. STAHL, Examiner. 

1. A CARTRIDGE FOR IGNITING GAS MIXTURES WITH AIR OR OXYGEN REQUIRING A HOT IGNITION FLAME BURNING FOR A RELATIVELY LONG PERIOD OF TIME, ESPECIALLY FOR GASEOUS PROPELLANTS OF ENGINES, COMPRISING A GENERALLY TUBULAR CASE HAVING REARWARD AND FORWARD ENDS; A BOTTOM PIECE SUBSTANTIALLY CLOSING THE REARWARD END OF SAID CASE; A GENERALLY TUBULAR BURNING CHARGE WITHIN SAID CASE FORMING A GENERALLY AXIALLY EXTENDING FIRING CHANNEL SUBSTANTIALLY VOID OF PROPELLANT CHARGE; MEANS AT THE FORWARD END OF SAID CASE ADJACENT TO SAID CHARGE FOR IGNITING SAID BURNING CHANGE INCLUDING AT LEAST ONE SHEET OF IGNITION POWER EXTENDING GENERALLY TRANSVERSE TO THE AXIS OF SAID CHANNEL; SAID SHEET BEING PROVIDED WITH AT LEAST ONE APERTURE ALIGNED WITH SAID CHANNEL; THE AREA OF THE CROSS SECTION OF SAID APERTURE BEING SUBSTANTIALLY LESS THAN THE AREA OF THE CROSS SECTION OF SAID CHANNEL; SHEET MEANS ADJACENT SAID APERTURNED SHEET FOR COMPLETELY CLOSING SAID APERTURE AND SAID CHANNEL; AND SAID SHEET AND SHEET MEANS BEING THE SOLE END CLOSURE FOR SAID CARTRIDGE CASE. 